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Evidence for a Permain-Triassic Mascon Wilkes Land, AntarcticaProf. Ralph R.B. von Frese , Ohio State University Indeed, its remarkable antipodal relationship with the Siberian Traps and level of isostatic disturbance broadly date it to the beginning of the greatest extinction of life on Earth about 260 million years ago. Thus, in addition to apparently triggering the ‘Great Dying’ at the end of the Permian, the impact also may have contributed to the development of the hotspot which produced the Siberian Traps and now is under Iceland. The impact extensively thinned and disrupted the Wilkes Land crust where the Kerguelen hotspot and Gondwana rifting developed, but left the conjugate Australian block relatively undisturbed. Up to several kilometers of covering glacial ice greatly limits direct geological testing of the inferred impact basin. Thus, the most viable and perhaps expedient test of this interpretation is to survey the prospective crater for confirming airborne gravity and magnetic anomalies. Additional information and images about this discovery may be found at: Space.com: Spaceref.com article:
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The P/T Colloquium is
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The GRACE satellite mission is resolving significant new details of the gravity field of Antarctica. A prominent positive free-air gravity anomaly mapped over a roughly 500-km diameter subglacial basin is consistent with a giant meteorite impact at (70oS, 120oE) in north central Wilkes Land between the Gamburtsev and Transantarctic Mountains of East Antarctica. The inferred giant impact crater is nearly three times the size of the Chicxulub crater. It must have formed before the Cretaceous break-up of Australia and East Antarctica because the coastline cuts across its projected ring faults. 
